1. Field of the Invention
The present invention relates to a communication method for use in a communication system constructed by connecting a pair of networks, which are constructed by connecting a plurality of relay units to which one or more than two node terminals are connected respectively via data transfer lines, via a gate way to execute data exchange between the node terminals, the relay terminals, or the node terminal and the relay terminal. More particularly, the present invention relates to a communication method capable of surely transmitting communication data to a destination while remarkably increasing data transmission capability per unit time, a communication system, and a gate way used in this communication system.
2. Description of the Prior Art
In the prior art, as disclosed in Patent Application Publication (KOKAI) 59-62245, for example, a data communication system has been widely known in which a plurality of local area networks (referred to as xe2x80x9cLAN""sxe2x80x9d hereinafter) used to execute data exchange between a plurality of stations are connected via gate ways to enable data exchange between LANs.
According to the technology disclosed in the above Publication, in addition to a transmitter/receiver address for designating the transmitter and the receiver of data respectively, a transmitting or receiving station address indicating the data transmitting or receiving station and a network address indicating the network to which the data transmitting or receiving station belongs have been provided in the transmitter/receiver address of the communication data. Hence, even if data communication is to be carried out beyond its own network, certain data communication between different LAN""s has been made possible by referring to these addresses upon data communication.
However, in the above communication system in the prior art, since there has existed a large variety of addresses to be attached to the communication data, an information writing area of relatively large capacity must be prepared as address writing area in the communication data. Therefore, such a problem to be solved has been involved in the prior art that this becomes a barrier upon increasing data transmission capability per unit time.
The present invention has been made in light of the above circumstances, and it is an object of the present invention to provide a communication method, a communication system, and a gate way used in the communication system, which are capable of transmitting communication data to a destination without fail while increasing remarkably data transmission capability per unit time, by describing previously source/destination addresses in a small amount of address describing area provided in the communication data, then transmitting the communication data, in which the source/destination addresses are described, to a destination by the relay units, then decoding the source/destination addresses included in received communication data by the gate way, then deciding whether or not the source and the destination belong to a same network, by the gate way based on decoded source/destination addresses and attribution identification information stored previously, and then selecting an appropriate route as the destination of the communication data based on a result of attribution decision and then transmitting the communication data to the destination via the selected route by the gate way.
In order to achieve the above object of the present invention, there is provided a communication method for use in a communication system constructed by connecting a pair of networks, which are constructed by connecting a plurality of relay units to which one or more than two node terminals are connected respectively via data transfer lines, via a gate way so as to execute data exchange between the node terminals, the relay units, or the node terminal and the relay unit, the communication method comprising the steps of: describing source/destination addresses previously in an address describing area provided in communication data as transmission object by the relay units; transmitting the communication data, in which the source/destination addresses are described, to a destination by the relay units; decoding the source/destination addresses included in received communication data by the gate way; deciding whether or not a source and the destination belong to a same network, by the gate way based on the decoded source/destination addresses and attribution identification information stored previously; and selecting an appropriate route as the destination of the communication data based on a result of attribution decision and then transmitting the communication data to the destination via the selected route by the gate way.
According to the present invention, first the relay units transmits the communication data, in the address describing area of which the source/destination addresses are described, to the destination. Then the gate way decodes the source/destination addresses included in received communication data, then decides whether or not the source and the destination belong to the same network based on the decoded source/destination addresses and attribution identification information stored previously, then selects the appropriate route as the destination of the communication data based on the result of attribution decision, and then transmits the communication data to the destination via the selected route.
Hence, according to the present invention, the communication data can be transmitted surely to the destination while increasing remarkably data transmission capability per unit time only by describing the source/destination addresses previously in a small amount of the address describing area provided in communication data.
In the preferred embodiment of the present invention, the appropriate route selecting step and the communication data transmitting step by the gate way comprise the steps of: selecting a route for own network, to which the source belongs, as the destination of the communication data by the gate way when it has been decided based on a result of the attribution decision that the source and the destination belong to the same network, and transmitting the communication data to the destination via the selected route for own network by the gate way.
According to this embodiment, when it has been decided based on the result of the attribution decision that the source and the destination belong to the same network, the gate way selects a route for own network, to which the source belongs, as the destination of the communication data, and then transmits the communication data to the destination via the selected route for own network.
In the preferred embodiment of the present invention, the appropriate route selecting step and the communication data transmitting step by the gate way comprise the steps of: selecting a route for other network, to which the source does not belong, as the destination of the communication data by the gate way when it has been decided based on a result of the attribution decision that the source and the destination do not belong to the same network, and transmitting the communication data to the destination via the selected route for other network by the gate way.
According to this embodiment, when it has been decided based on a result of the attribution decision that the source and the destination do not belong to the same network, the gate way selects a route for other network, to which the source does not belong, as the destination of the communication data, and then transmits the communication data to the destination via the selected route for other network.
In order to achieve the above object of the present invention, there is provided a communication method for use in a communication system constructed by connecting a pair of networks, which are constructed by connecting a plurality of relay units to which one or more than two node terminals are connected respectively via data transfer lines, via a gate way so as to execute data exchange between the node terminals, the relay units, or the node terminal and the relay unit, the communication method comprising the steps of: describing source/destination addresses previously in an address describing area provided in communication data as transmission object by the relay units; transmitting the communication data, in which the source/destination addresses are described, to a destination by the relay units; decoding the source/destination addresses included in received communication data by the gate way; deciding whether or not a source and the destination belong to a same network, by the gate way based on the decoded source/destination addresses and attribution identification information stored previously; and selecting a route for own network, to which the source belongs, as the destination of the communication data by the gate way when it has been decided based on a result of the attribution decision that the source and the destination belong to the same network, otherwise selecting a route for other network, to which the source does not belong, as the destination of the communication data by the gate way when it has been decided based on a result of the attribution decision that the source and the destination do not belong to the same network, and then transmitting the communication data to the destination via the selected route for one of own network and other network by the gate way.
According to the present invention, first the relay units transmits the communication data, in the address describing area of which the source/destination addresses are described, to the destination. Then the gate way decodes the source/destination addresses included in received communication data, then decides whether or not the source and the destination belong to the same network based on decoded source/destination addresses and attribution identification information stored previously, then selects a route for own network, to which the source belongs, as the destination of the communication data by the gate way when it has been decided based on a result of the attribution decision that the source and the destination belong to the same network, otherwise selects a route for other network, to which the source does not belong, as the destination of the communication data by the gate way when it has been decided based on a result of the attribution decision that the source and the destination do not belong to the same network, and then transmits the communication data to the destination via the selected route for one of own network and other network.
Hence, according to the present invention, the communication data can be transmitted surely to the destination while increasing remarkably data transmission capability per unit time only by describing the source/destination addresses previously in a small amount of the address describing area provided in communication data.
In order to achieve the above object of the present invention, there is provided a communication system constructed by connecting a pair of networks, which are constructed by connecting a plurality of relay units to which one or more than two node terminals are connected respectively via data transfer lines, via a gate way so as to execute data exchange between the node terminals, the relay units, or the node terminal and the relay unit, each of the relay units comprising: transmitting means for transmitting the communication data, in an address describing area of which the source/destination addresses are described, to a destination; and the gate way comprising: decoding means for decoding the source/destination addresses included in received communication data; identification information storing means for storing attribution identification information which correlate addresses of the node terminals and the relay units, which belong to a pair of networks respectively, with respective networks; attribution deciding means for deciding whether or not a source and the destination belong to a same network, based on the source/destination addresses decoded by the decoding means and the attribution identification information stored in the identification information storing means; and route selecting means for selecting an appropriate route as the destination of the communication data based on a result of attribution decision carried out by the attribution deciding means, and then transmitting the communication data to the destination via the selected route.
According to the present invention, at first the transmitting means of the relay units transmits the communication data, in an address describing area of which the source/destination addresses are described, to a destination. Then, in the gate way, the decoding means of the gate way decoding the source/destination addresses included in received communication data. The identification information storing means stores attribution identification information which correlate addresses of the node terminals and the relay units, which belong to a pair of networks respectively, with respective networks. Then, the attribution deciding means decides whether or not the source and the destination belong to the same network, based on the source/destination addresses decoded by the decoding means and the attribution identification information stored in the identification information storing means. Then, the route selecting means selects the appropriate route as the destination of the communication data based on a result of attribution decision carried out by the attribution deciding means, and then transmits the communication data to the destination via the selected route.
Hence, according to the present invention, the communication data can be transmitted surely to the destination while increasing remarkably data transmission capability per unit time only by describing the source/destination addresses previously in a small amount of the address describing area provided in communication data.
In order to achieve the above object of the present invention, there is provided a gate way for use in a communication system constructed by connecting a pair of networks, which are constructed by connecting a plurality of relay units to which one or more than two node terminals are connected respectively via data transfer lines, via a gate way so as to execute data exchange between the node terminals, the relay units, or the node terminal and the relay unit, the gate way comprising: four input/out terminals including a pair of first and second input terminals and a pair of first and second output terminals, the first input terminal and the first output terminal being connected to one network and the second input terminal and the second output terminal being connected to other network to thus connect the pair of networks mutually; decoding means for decoding source/destination addresses included in the communication data received from the source; identification information storing means for storing attribution identification information which correlate addresses of the node terminals and the relay units, which belong to a pair of networks respectively, with respective networks; attribution deciding means for deciding whether or not a source and a destination belong to a same network, based on the source/destination addresses decoded by the decoding means and the attribution identification information stored in the identification information storing means; and route selecting means for selecting one of the first output terminal and the second output terminal as the destination of the communication data received via the first input terminal and also selecting one of the first output terminal and the second output terminal as the destination of the communication data received via the second input terminal, based on a result of attribution decision carried out by the attribution deciding means, and then transmitting the communication data to the destination via selected output terminal.
According to the present invention, first the decoding means decodes source/destination addresses included in the communication data received from the source. Then, the attribution deciding means decides whether or not the source and the destination belong to a same network, based on the source/destination addresses decoded by the decoding means and the attribution identification information stored in the identification information storing means. Then, the route selecting means selects one of the first output terminal and the second output terminal as the destination of the communication data received via the first input terminal and also selects one of the first output terminal and the second output terminal as the destination of the communication data received via the second input terminal, based on the result of attribution decision carried out by the attribution deciding means, and then transmits the communication data to the destination via selected output terminal.
Hence, according to the present invention, the communication data can be transmitted surely to the destination while increasing remarkably data transmission capability per unit time only by describing the source/destination addresses previously in a small amount of the address describing area provided in communication data.
In the preferred embodiment of the present invention, the route selecting means selects an output terminal for own network, to which the source belongs, as the destination of the communication data when it has been decided, as a result of the attribution decision carried out by the attribution deciding means, that the source and the destination belong to the same network, otherwise selects an output terminal for other network, to which the source does not belong, as the destination of the communication data when it has been decided, as a result of the attribution decision carried out by the attribution deciding means, that the source and the destination do not belong to the same network, and then transmits the communication data to the destination via the selected output terminals for one of own network and other network.
According to this embodiment, the route selecting means selects an output terminal for own network, to which the source belongs, as the destination of the communication data when it has been decided, as a result of the attribution decision carried out by the attribution deciding means, that the source and the destination belong to the same network, otherwise selects an output terminal for other network, to which the source does not belong, as the destination of the communication data by the gate way when it has been decided, as a result of the attribution decision carried out by the attribution deciding means, that the source and the destination do not belong to the same network, and then transmits the communication data to the destination via the selected output terminal for one of own network other network.
In the preferred embodiment of the present invention, a gate way further comprises mixing means for multiplexing received communication data when the first output terminal has been selected as the destination of the communication data received via the first input terminal and the second input terminal respectively and then transmitting multiplexed communication data to the destination via the selected first output terminal, otherwise multiplexing received communication data when the second output terminal has been selected as the destination of the communication data received via the first input terminal and the second input terminal respectively and then transmitting multiplexed communication data to the destination via the selected second output terminal.
According to this embodiment, the mixing means for multiplexing received communication data when the first output terminal has been selected as the destination of the communication data received via the first input terminal and the second input terminal respectively and then transmitting multiplexed communication data to the destination via the selected first output terminal, otherwise multiplexing received communication data when the second output terminal has been selected as the destination of the communication data received via the first input terminal and the second input terminal respectively and then transmitting multiplexed communication data to the destination via the selected second output terminal.
In order to achieve the above object of the present invention, there is provided a gate way for use in a communication system constructed by connecting a pair of networks, which are constructed by connecting a plurality of relay units to which one or more than two node terminals are connected respectively via data transfer lines, via a gate way so as to execute data exchange between the node terminals, the relay units, or the node terminal and the relay unit, the gate way comprising: four input/out terminals including a pair of first and second input terminals and a pair of first and second output terminals, the first input terminal and the first output terminal being connected to one network and the second input terminal and the second output terminal being connected to other network to thus connect the pair of networks mutually; first decoding means for decoding source/destination addresses included in the communication data received from the relay unit belonging to one of the pair of networks; second decoding means for decoding the source/destination addresses included in the communication data received from the relay unit belonging to other of the pair of networks; first identification information storing means for storing addresses of the node terminals and the relay units belonging to one of the pair of networks as first attribution identification information; second identification information storing means for storing addresses of the node terminals and the relay units belonging to other of the pair of networks as second attribution identification information; first attribution deciding means for deciding whether or not a source and a destination belong to one of the pair of networks, based on the source/destination addresses decoded by the first decoding means and the first attribution identification information stored in the first identification information storing means; second attribution deciding means for deciding whether or not a source and a destination belong to other of the pair of networks, based on the source/destination addresses decoded by the second decoding means and the second attribution identification information stored in the second identification information storing means; first route selecting means for selecting a route for one of the first output terminal and the second output terminal as the destination of the communication data received via the first input terminal, based on a result of attribution decision carried out by the first attribution deciding means, and then transmitting the communication data to the destination via the selected route for one of the first output terminal and the second output terminal; and second route selecting means for selecting a route for other of the first output terminal and the second output terminal as the destination of the communication data received via the second input terminal, based on a result of attribution decision carried out by the second attribution deciding means, and then transmitting the communication data to the destination via the selected route for other of the first output terminal and the second output terminal.
According to the present invention, since the gate way is constructed to be divided into the collective functional means for executing various processes of the communication data which are received from the relay units belonging to one of the networks, and the collective functional means for executing various processes of the communication data which are received from the relay units belonging to the other of the networks, such gate way which enables to separate a pair of networks easily can be achieved.
In the preferred embodiment of the present invention, the route through which the communication data received via the first input terminal are supplied to the second output terminal and the route through which the communication data received via the second input terminal are supplied to the first output terminal are constructed by any communication medium which enable transmission of the communication data.
According to this embodiment, since the route through which the communication data received via the first input terminal are supplied to the second output terminal and the route through which the communication data received via the second input terminal are supplied to the first output terminal are constructed by any communication medium which enable transmission of the communication data, data exchange between the pair of networks can be readily achieved via appropriate communication medium even when one and the other of the networks are placed at mutually separated locations, for example.
The nature, principle and utility of the invention will become more apparent from the following detailed description when read in conjunction with the accompanying drawings.